diff options
| author |   Alistair Popple <apopple@nvidia.com> | 2021-06-30 18:54:35 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-01 11:06:04 -0700 |
| commit | 8f187163eb890d6d2a53f7efea2b6963fe9526e2 (patch) | |
| tree | 7f7483626a28203dc07713a313bd62a4a002abe3 /drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h | |
| parent | nouveau/svm: refactor nouveau_range_fault (diff) | |
| download | wireguard-linux-8f187163eb890d6d2a53f7efea2b6963fe9526e2.tar.xz wireguard-linux-8f187163eb890d6d2a53f7efea2b6963fe9526e2.zip | |
nouveau/svm: implement atomic SVM access
Some NVIDIA GPUs do not support direct atomic access to system memory via
PCIe. Instead this must be emulated by granting the GPU exclusive access
to the memory. This is achieved by replacing CPU page table entries with
special swap entries that fault on userspace access.
The driver then grants the GPU permission to update the page undergoing
atomic access via the GPU page tables. When CPU access to the page is
required a CPU fault is raised which calls into the device driver via MMU
notifiers to revoke the atomic access. The original page table entries
are then restored allowing CPU access to proceed.
Link: https://lkml.kernel.org/r/20210616105937.23201-11-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h')
| -rw-r--r-- | drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h index a2b179568970..f6188aa9171c 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h @@ -178,6 +178,7 @@ void nvkm_vmm_unmap_region(struct nvkm_vmm *, struct nvkm_vma *); #define NVKM_VMM_PFN_APER 0x00000000000000f0ULL #define NVKM_VMM_PFN_HOST 0x0000000000000000ULL #define NVKM_VMM_PFN_VRAM 0x0000000000000010ULL +#define NVKM_VMM_PFN_A 0x0000000000000004ULL #define NVKM_VMM_PFN_W 0x0000000000000002ULL #define NVKM_VMM_PFN_V 0x0000000000000001ULL #define NVKM_VMM_PFN_NONE 0x0000000000000000ULL |